Wikipedia:Reference desk/Archives/Science/2024 August 13

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

August 13

Dogs barking at some people

A friend of mine told me that on two recent occasions dogs started barking uncontrollably at a new acquaintance of her, a young man, in both cases much to the embarrassment of the dog owners, who could not silence their dogs and saw no other solution than to walk their dogs away. She did not see anything in his behaviour or demeanor that could have triggered this and asked me for an explanation. Now this is purely anecdotal, and I've heard similar anecdotes before. My question: is there evidence (beyond the anecdotal) for some people unwittingly tending to alarm dogs more than others, and if so, have possible science-based explanations been offered for the phenomenon?  --Lambiam 00:02, 13 August 2024 (UTC)

There seems to be evidence that dogs can smell biological changes in humans which indicate the presence of a disease (COVID, cancer, etc). Medical detection dogs exist, but they must be trained to detect VOCs (volatile organic compounds). Of course, canines may bark for multiple other reasons. --2001:871:6A:1B71:4CD8:804D:2688:FD83 (talk) 06:28, 13 August 2024 (UTC) Oops, --Cookatoo.ergo.ZooM (talk) 06:29, 13 August 2024 (UTC)

Who knows what it's like to be a dog. It's such a diverse group. I know a Siberian Husky street dog with an apparent racist hatred of white people. He's a good dog though, mostly. My dog is more aggressive towards male strangers but will change direction and try to follow attractive female strangers, which is a little awkward. He also barks aggressively at fallen leaves, beetles (no size dependency), mynah birds, skinks, many things...not seeing a pattern so far. They can smell adrenaline of course, which might explain some cases. Sean.hoyland (talk) 07:51, 13 August 2024 (UTC)

Did she ever see her new acquaintance in sunlight? —Tamfang (talk) 16:57, 16 August 2024 (UTC)

Lambiam, if you could provide the missing details, I believe we could solve this. Find out what type of breed the dogs are and what kind of work her acquaintance does. If he's into construction, landscpaing, or works in a mortuary, for example, he might have some very complex scents on him that are disturbing the dogs. I think it's also possible that it doesn't mean anything at all. Some of the dogs in my neighborhood will bark uncontrollably at strangers who talk to their owners. If they don't receive the voice command to be quiet, they will continue. Viriditas (talk) 23:18, 19 August 2024 (UTC)

Skin disorder

I have just got off the bus, where I was sitting behind a woman with globules all over her body. I have looked at List of skin conditions, (the longest article I have ever encountered), but am none the wiser. What is the name of it? 2A00:23D0:E1D:2D01:B1A1:2846:AA72:4934 (talk) 14:19, 13 August 2024 (UTC)

Lipoma...maybe. Sean.hoyland (talk) 14:56, 13 August 2024 (UTC)

Could also be neurofibromatosis. nmael^talk 15:08, 13 August 2024 (UTC)

Could be monkeypox. Graeme Bartlett (talk) 11:42, 17 August 2024 (UTC)

Inches and lines

I'm working on Phobaeticus annamallayanus, described by James Wood-Mason. As a taxon author he is quite unhelpful, since he left only a brief and vague description ([1], see the second entry, Phibalosoma annamallayanum). Worse, he gave his measurements in inches and lines, something which was apparently in vogue at the time but is a pain at the moment, since a "line" can be anywhere between a tenth and fortieth of an inch. I'm willing to make approximations like "between two and three inches", but that's less than ideal. Does anyone have any idea which meaning of line 19th century entomologists likely meant?

Secondly, at the start of his measurements, he gives the total length as "8 in 9" lines. What does that mean? Surely not ⁸/₉.

Thank-you for any help you can provide. Cheers, Cremastra (talk) 16:20, 13 August 2024 (UTC)

In the last century, there was a useful booklet called Wightman's Arithmetical Tables. The first entry for Long Measure was "12 lines = 1 inch". This is also noted here [2]. These books have many alternative versions of the Thirty days hath September rhyme of which I was previously unaware. 91.234.214.10 (talk) 16:38, 13 August 2024 (UTC)

I feel that claiming it can mean anything from a tenth to a fortieth of an inch is an exaggeration. The different definitions were based on usage. It is not reasonable to think that he would be using the Russian ballistic definition of a line when referring to the size descriptions of an insect. The only real issue is that 1/12 of an inch was the standard for botany and entomology until the mid-1800's. Then, some (not all) areas of science (primarily the French) tried to "decimalize" it to 1/10 of an inch. So, the question is, did Wood-Mason use the newfangled definition of 1/10 of an inch or the long-standing definition of 1/12 of an inch. I personally see no reason he would update all of his research, which took place long before the 1/10 of an inch definition was introduced, to a new measurement. 12.116.29.106 (talk) 16:49, 13 August 2024 (UTC)

Agree that one twelfth is the most likely. See The Measures, Weights & Moneys of All Nations (p. 50) of 1890 which says: "A line is 1/12th part of an inch".

Also Great Britain's New Proposed Decimal Albert System of Weights, Measures and Coins (p.32) of 1869 which has "1 Line, or inch 1/12".

And an American textbook, Higher Arithmetic, Or, The Science and Application of Numbers (p. 150) of 1848 which says: "The inch is commonly divided into eigths or tenths; sometimes however, it is divided into twelfths which are called lines".

Alansplodge (talk) 17:40, 13 August 2024 (UTC)

The previous entry for Phibalosoma acanthopus (which should be the same as Phobaeticus serratipes, see [3]) gives us a simple math problem: "4 in. 6.5 lines + 12.5 lines = 5 in. 7 lines." That only works if one inch is twelve lines. The total length of "8 in. 9 lines" means 8 inches and 9 lines. --Amble (talk) 17:58, 13 August 2024 (UTC)

@Amble The total length of "8 in. 9 lines" means 8 inches and 9 lines Oh, I'm a moron. I didn't see the dot after "in".

Well, at least that wasn't too complicated.

Thanks for spotting the clue in the above entry; I was hoping it was 1/12, since that seemed standard, but I didn't want to guess. Thanks also to IPs and @Alansplodge for their research.

Cheers, Cremastra (talk) 18:58, 13 August 2024 (UTC)

In such cases I use BHL's "Search inside" button to search for "in. 10" and "in. 11". Indeed under "Phibalosoma acanthopus" is a "1 in. 11.75 lines". So clearly 12 lines per inch. JMCHutchinson (talk) 14:24, 15 August 2024 (UTC)